Poly(arylene ether) resins have been blended with polyamide resins to provide compositions having a wide variety of beneficial properties such as heat resistance, chemical resistance, impact strength, hydrolytic stability and dimensional stability.
These beneficial properties are desirable in a wide variety of applications and the shapes and sizes of the parts required for these applications vary widely. As a result there is a variety of forming or molding methods employed such as injection molding, compression molding and extrusion. Each molding method requires a different set of physical characteristics for the polymer being molded so a blend which is suitable for high shear/high pressure processes such as injection molding may not be suitable for low pressure/low shear processes such as blow molding, sheet extrusion and profile extrusion. For example, profile extrusion requires that a polymer blend be forced through a shaped die (a profile) and maintain the extruded shape until cooled. The extruded shape may be further manipulated while the polymer blend is still malleable through the use of shaping tools and the shaped profile must retain its shape after manipulation. Therefore blends employed in low pressure/low shear processes typically have fairly high melt viscosity (low melt flow indices) as well as high melt strength.
In some applications it is desirable that the extruded shape be electrostatically coatable which requires use of an electrically conductive material. Unfortunately the inclusion of electrically conductive fillers in high melt viscosity blends can be problematic, particularly in a multi phase polymer blends such as a poly(arylene ether)/polyamide blend. Furthermore, flame retardancy of electrically conductive high melt viscosity blends can be difficult to achieve.